Carlos Berlocq and Juan Monaco each won their matches Friday to give Argentina a 2-0 lead over Germany in the first round of the Davis Cup, putting the South Americans one win away from the quarterfinals.
Berlocq defeated Philipp Kohlschreiber in the first singles match when the German retired with a left hamstring injury while leading 5-4 in the fifth set. Team officials said Kohlschreiber was having trouble walking after the match and it was unclear whether he will be available for Sunday's reverse singles.
Monaco beat Florian Mayer 6-7 (4), 6-3, 6-3, 6-4 to set the stage for David Nalbandian and Horacio Zeballos to wrap up the series against Tobias Kamke and Christopher Kas in Saturday's doubles.
Berlocq beat Kohlschreiber 3-6, 7-5, 2-6, 6-4, 4-5.